I trap pollen at a home yard with 24 hives. In 2006 we had a monster season for honey production 
and the hives with pollen traps wintered well, in fact better then most yards and my experience 
has been that pollen trapping does not harm the bees wintering success

In 2007 we had bad drought into the end of July then non-stop rain for the next month. Honey 
production was average to poor in late season here in MN. The pollen trap yard at home had nice 
populations but no brood in sept.  As of yesterday, it looks like a 60% loss in the pollen yard hives

Five miles away I have a yard of 18 hives of the same bees *russian hybrid" and I found 2 dead out 
of 18. These hives had no brood too in Sept but we never trapped any pollen 

I should mention that both yards all had new queens in May of 2007 on clean equipment.  They 
were part of an effort to clean out italian and carniolan bees and replace with russian stock. So 
they were sister yards except for the pollen trapping. 

 We wrapped in late November and a few days later we had the start of an early cold winter that 
has given way to a mild winter in late December and early Jan

Seems like the pollen trapping may have led to their demise as we have a multi year history of 
good wintering in these 2 yards.  With the discussion of nutrition lately the pollen trapping and 
weather in August makes me wonder what role that played. Hard to explain the losses otherwise.

Other thoughts? 

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